Computers and servers now are designed with very large internal memories requiring very large numbers of memory modules. Each memory module or memory chip requires a plurality of connections, both to and through the circuit board onto which it is mounted and to the circuit board connectors, which then may be connected to mating connectors as part of the host computer. Similarly, a large and complex central electronic portion of the computer is required to control, address and efficiently utilize the large internal memories. The interconnection of the circuit board connectors on the memory panels and central electronic complex panels to the computer connectors effectively connects the memory or other electronic modules to the circuitry of the host computer.
In order to make a computer easily maintainable and repairable, as necessary, the memory modules and the components of the central electronic system are mounted on a plurality of removable and replaceable electronic circuit boards. These electronic circuit boards are mounted within rigid frames which permit the circuit boards and associated circuit board connectors to be removed from the computer and changed out with a replacement assembly providing protection from the high level forces necessary for insertion and removal. The completed assembly of the memory modules, circuit board, frame and connectors are commonly collectively referred to as a "book." Additionally a central electronic complex for the computer may be made into a "book" for the same reasons.
Each book must be easily removable and replaceable with respect to the computer framework or connections to the electronics of the computer. Removal and re-connection of books during operation of the computer or server is referred to as "hot plugging." As it is common for computers to be operational at all times, maintenance and repair must be accomplished to whatever extent possible while the computer is operating, thus requiring hot plugging. Thus, the installation and removal of the book must be accomplished to insure minimal, if any, disruption to the continued computer operation.
With a large memory capacity or a large number of electronic components necessary for a central electronic complex assembled as a book, the number of connections required between the book and computer circuits can and does become quite large. For example, a typical connector may have 1112 pin-in-socket interfaces. More or fewer such connections may be incorporated as dictated by the type and the number of chips or electronic components on the electronic circuit board of the book.
A typical book of memory or central electronic complex book may require connection forces of up to 190 pounds or disconnection forces of 60 pounds or more, force levels which generally are not manageable by service or assembly personnel without an additional apparatus to assist and evenly apply the connection or disconnection forces to the book frame. This connection or disconnection force is the cumulative force made up of the combined frictional resistance forces of connection or disconnection for each individual pin and socket connection. Even and proper distribution of the connection and disconnection forces to the book frame is necessary to prevent any potential bending or damaging of the pins and/or misconnection of any connector on the electronic circuit board of the book.
A prior art lever and latching system which has been used to aid in the insertion, connection, disconnection and removal of a electronic book in a computer is illustrated in FIG. 1. The lever and latching system in FIG. 1 is such that the maximum utilization of the space within the computer, by maximization of the dimensions of the circuit board within a particular book, has been compromised both by the volume of space required for the latching and retention apparatus as well as the resulting unusable space between the latches. The disposition of the latches on the exposed, external planar surface 12 of the tailstock 10 by the positioning of bracket 14 and pivot 18, as illustrated, consumes excessive space. Additionally, the disposition of latch 22 to engage the latching surface 32 of bracket 14 further requires the latch arms 16 to be displaced significantly from tailstock 10 in order to accommodate the latch structure and permit manual access to the release member 28. With the consumption of available space by the latch arm 16, the remaining space is unduly limited within the computer frame for the book including the electronic circuit board and the electronic modules.